Pair-wise additive force fields provide fairly accurate predictions, through classical molecular simulations, for a wide range of structural, thermodynamic, and dynamical properties of many materials. However, one key property that has not been well captured is the static dielectric constant, which characterizes the response of a system to an applied electric field and is important in determining the screening of electrostatic interactions through a system. A simple correction has been found to provide a relatively robust method to improve the estimate of the static dielectric constant from molecular simulations for a broad range of compounds. This approach accounts for the electronic contribution to molecular polarizability and assumes that the charges that couple a molecule to an applied electric field are proportional to the effective force field charges. In this work, we examine how this correction performs for systems at different temperatures and for binary mixtures. Using a value for the electronic polarizability, based on the experimental index of refraction, and a charge scaling factor, determined at a single temperature, we find that the static dielectric constant can be predicted remarkably well, in comparison to the experimentally measured values. This provides good evidence that the effective charges that appear in pair-wise additive force fields developed to reproduce the potential energy surface of a system are not the same as those that determine the static dielectric constant; however, they can be captured in a relatively simple manner, which is dependent on the particular force field.It is challenging to identify effective electrocatalysts for nitrogen reduction in order to advance electrochemical nitrogen fixation under ambient conditions using methods that are powered by renewable energy. Silicon carbide was investigated computationally as a metal-free, surface-derived catalyst for the electrocatalytic nitrogen reduction reaction. As demonstrated by first-principle calculations, Si-terminated and C-terminated surfaces, with the Si and C as active sites, are all reactive for dinitrogen capture and activation, resembling the catalytic behavior of popular B-based electrocatalysts, but the latter (C-terminated) offers an ultralow over-potential of 0.39 V, which is lower than most metals and alloys, while retarding hydrogen evolution. This research enriches the design of catalysts for dinitrogen fixation under ambient conditions, and also highlights a new direction for Si-based materials for nitrogen reduction.We report a label-free and "signal-on" homogeneous photoelectrochemical cytosensing system for ultrasensitive detection of cancer cells, which is a truly homogeneous PEC cytosensing system without the photoactive material immobilization and target recognition probe modification, providing a new avenue in early and accurate cancer diagnosis and clinical analysis.Aureins, natural active peptides extracted from skin secretions of Australian bell frogs, have become a research focus due to the antitumor effects caused by lysing cell membranes. However, clinical translation of Aureins is still limited by non-selective toxicity between normal and cancer cells. Herein, by structure-activity relationship analysis and rational linker design, a dual-function fusion peptide RA3 is designed by tactically fusing Aurein peptide A1 with strong anticancer activity, with a tri-peptide with integrin αvβ3-binding ability which was screened in our previous work. Rational design and selection of fusion linkers ensures α-helical conformation and active functions of this novel fusion peptide, inducing effective membrane rupture and selective apoptosis of cancer cells. The integrin binding and tumor recognition ability of the fusion peptide is further validated by fluorescence imaging in cell and mouse models, in comparison with the non-selective A1 peptide. Meanwhile, increased stability and superior therapeutic efficacy are achieved in vivo for the RA3 fusion peptide. Our study highlights that aided by computational simulation technologies, the biomimetic fusion RA3 peptide has been successfully designed, surmounting the poor tumor-selectivity of the natural defensive peptide, serving as a promising therapeutic agent for cancer treatment.In this work, we computationally study the photoinduced electron transfer in fullerene inclusion complexes of two phenine nanotubes pre-pNT⊃C70 and pNT⊃C70 and their nanographene analog [4]CHBC⊃C70. https://www.selleckchem.com/products/nu7441.html Charge separation is shown to efficiently occur in [4]CHBC⊃C70. In contrast, the electron transfer process between the host and guest units in the pre-pNT⊃C70 and pNT⊃C70 complexes is blocked by the structural changes incorporated in the nanographene framework.The increasing emergence and spread of antimicrobial resistance are urgent and important global challenges today. The clinical pipeline is lacking in innovative drugs that avoid the development of drug resistance. Macromolecular antimicrobials kill bacteria and fungi through physical disruptions to the cell membrane, which is difficult for microbes to overcome. Recently, we reported antimicrobial polycarbonates that kill microbes via two different mechanisms. Polycarbonates functionalized with quaternary ammonium disrupted the lipid bilayer membrane of the microbes, while polycarbonates functionalized with guanidinium translocated the membrane and precipitated cytosolic components. We hypothesized that the combination of these two distinct mechanisms would result in a more than additive increase in antimicrobial efficacy. Block and random copolymers containing both cationic groups had similar minimum inhibitory concentrations (MICs) as the guanidinium homopolymer on 5 representatives of the ESKAPE pathogens. a basic understanding of polymer design with different cationic groups.The primordial origin of abiotic nitrogen fixation, which is not dependent on prokaryotes, reflects the importance of available nitrogenous compounds as an essential requirement for the emergence of life and evolutionary biodiversity. It has been hypothesized that synthesis of oxidized nitrogen in the form of nitrate (NO3-) and nitrite (NO2-), occurred in the prebiotic anoxic Hadean atmosphere. The sustained influx of atmospheric NO3- and NO2- into prebiotic Hadean oceans have been proposed to provide the essential substrates for abiotic synthesis of compounds such as ammonia (NH3) within oceanic alkaline hydrothermal vents in the seafloor. Because NH3 is an essential chemical precursor for nitrogen-containing molecular components of proteins and nucleic acids, abiotic production in high concentrations within Hadean oceanic alkaline hydrothermal vents is required for the emergence of diverse life forms. The chemical evolution of nitrogenous compounds includes the functional development of alkaloids. This commentary aims to critically discuss the possible origin of nitrogen-containing alkaloids and evolutionary processes in higher organisms, including the diverse biomedical mechanisms involved.